Motion device for virtual reality interaction and virtual reality system

ABSTRACT

A motion device for a virtual reality interaction includes a core, a running belt carried by the core and a frame. The running belt is configured to wrap the core and capable of sliding on the outer surface of the core. The running belt includes a number of running belt units. A surface of each running belt unit facing the core is provided with a number of grooves, and each groove of each running belt unit is connected with a corresponding groove of an adjacent running belt unit through an elastic strap. The frame is located at a periphery of the running belt and is configured to carry the running belt and the core. A number of first balls are arranged between the frame and the running belt.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of a Chinese PatentApplication No. 201910688659.3, filed on Jul. 29, 2019, the contents ofwhich are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present application relates to the field of virtual reality, inparticular to a motion device for virtual reality interaction and avirtual reality system.

BACKGROUND

Virtual reality technology is a kind of computer simulation technologythat can create and experience a virtual world. By generating aninteractive three-dimensional dynamic visual scene with a computer,users can immerse themselves in a virtual environment and dualexperience of hearing and touch can be realized.

At present, when a virtual reality motion device realizes interactionbetween virtuality and reality through motions of lower limbs of a user,the user's experience through the mode of realizing the interactionbetween the virtuality and the reality is very poor due to limitedmotion range of the lower limbs of the user. Currently, virtual realitymotion devices capable of realizing omni-directional motion experiencesare generally complex in structure and poor in practical operability.

SUMMARY

In view of this, some exemplary embodiments of the present applicationpropose a motion device for virtual reality interaction, including:

a core;

a running belt carried by the core, the running belt configured to wrapthe core and capable of sliding on the outer surface of the core,wherein the running belt comprises a plurality of running belt units, asurface of each running belt unit facing the core is provided with aplurality of grooves, and each groove of each running belt unit isconnected with a corresponding groove of an adjacent running belt unitthrough an elastic strap; and

a frame located at a periphery of the running belt and configured tocarry the running belt and the core, wherein a plurality of first ballsare arranged between the frame and the running belt.

According to an aspect of the present disclosure, the outer surface ofthe core is provided with a plurality of sockets, and a second ball isarranged in each socket.

According to an aspect of the present disclosure, a cross section of therunning belt unit is hexagonal, and a corresponding groove is providedalong a perpendicular bisector of each side of the hexagon.

According to an aspect of the present disclosure, the running belt is anomni-directional running belt and comprises adjacent first and secondrunning belt units, the first running belt unit has a first stop walland a first groove, the first groove has a first slide rail, the secondrunning belt unit has a second stop wall and a second groove, the secondgroove has a second slide rail, the elastic strap has a first T-shapedend and a second T-shaped end, the first T-shaped end is configured toslide in the first slide rail and stop at the first stop wall, and thesecond T-shaped end is configured to slide in the second slide rail andstop at the second stop wall.

According to an aspect of the present disclosure, the core issubstantially ellipsoidal, and the ellipsoid has two oppositesubstantially planar main surfaces and an arc surface connecting the twomain surfaces.

According to an aspect of the present disclosure, the core is made ofrigid material, each running belt unit is made of a light metalmaterial, the elastic strap is a metal elastic strap, and the firstballs and the second balls are both metal balls.

According to an aspect of the present disclosure, as to the plurality ofsockets, connecting lines between centers of adjacent three sockets takeon an equilateral triangular shape.

According to an aspect of the present disclosure, the socket has aspherical segment shape, and a height of the spherical segment is ⅘ of aheight of the sphere.

According to an aspect of the present disclosure, the frame is providedwith a brush adjacent to an outer periphery of the main surface.

According to an aspect of the present disclosure, the surface of eachrunning belt unit facing the core is further provided with a pressuresensor.

According to an aspect of the present disclosure, the frame comprises anoil supply pipeline and an oil supply head arranged therein, the oilsupply pipeline is connected with an oil source, and the oil supply headis configured to supply oil to the socket through a gap when the gapoccurs between two adjacent running belt units. For example, the oilsupply head includes an oil brush to brush oil toward the socket and thesecond ball.

Some exemplary embodiments of the present application also provide avirtual reality system, including:

a virtual reality device including a receiver and a processor; and

a motion device for virtual reality interaction comprises:

a core;

a running belt carried by the core, the running belt configured to wrapthe core and capable of sliding on the outer surface of the core,wherein the running belt comprises a plurality of running belt units, asurface of each running belt unit facing the core is provided with aplurality of grooves, each groove of each running belt unit is connectedwith a corresponding groove of an adjacent running belt unit through anelastic strap, and the surface of each running belt unit facing the coreis further provided with a pressure sensor;

a frame located at a periphery of the running belt and configured tocarry the running belt and the core, wherein a plurality of first ballsare arranged between the frame and the running belt; and

a transmitter configured to transmit motion data of a user on therunning belt to the receiver of the virtual reality device,

wherein the processor is configured to establish a two-dimensionalcoordinate system according to the pressure sensor distribution of therunning belt, and combine the two-dimensional coordinate system with avirtual scene to create a three-dimensional real-time coordinate system.

According to an aspect of the present disclosure, the processor isfurther configured to: initialize the three-dimensional real-timecoordinate system according to an initial barycenter coordinate of theuser on the running belt and the virtual scene, wherein thethree-dimensional real-time coordinate system comprises a correspondencerelationship between actual coordinates and scene coordinates; andupdate the correspondence according to the movement of the user.

According to an aspect of the present disclosure, the processor isfurther configured to: determine actual coordinates of starting pointsand falling points of the user's feet according to pressure changesreceived by the pressure sensors corresponding to the barycentercoordinates of the user's feet when the user walks; determine a walkingdistance of the user in the virtual scene according to the actualcoordinates of the starting points and the falling points of the user'sfeet and the correspondence relationship between the actual coordinatesand the scene coordinates; and determine a walking speed of the user inthe virtual scene according to a time interval between the startingpoint and the falling point and the walking distance.

According to an aspect of the present disclosure, the processor isfurther configured to: determine an initial acceleration according tothe pressure changes received by the pressure sensors corresponding tothe barycenter coordinates of the user's feet and a weight of the userwhen the user jumps; determine a jumping height of the user according toa time interval between two adjacent landings of the user and theinitial acceleration; determine a horizontal displacement of the useraccording to the barycenter coordinates of the user's feet beforeleaving the ground and the barycenter coordinates of the user's feetafter landing.

According to an aspect of the present disclosure, the processor isfurther configured to adjust the walking distance or the horizontaldisplacement according to an error adjustment parameter.

According to an aspect of the present disclosure, the motion device forvirtual reality interaction is configured to: sense the user's motionthrough the pressure sensors of the running belt and generates motiondata; transmit the motion data of the user to the receiver of thevirtual reality device through the transmitter; wherein the virtualreality device is configured to: process the user motion data receivedby the receiver through the processor; display a virtual scene image;and adjust the virtual scene image according to the motion dataprocessing by the processor.

According to an aspect of the present disclosure, the motion dataincludes at least one of walking distance, walking speed, walkingdirection, jumping height, initial acceleration, and horizontaldisplacement of the user in the virtual scene.

Additional aspects and advantages of the present application will be setforth in part in the following description, and in part will be apparentfrom the following description, or may be learned by practice of theapplication.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the presentapplication will become apparent and readily understood from thefollowing description of some exemplary embodiments taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view of a motion device forvirtual reality interaction according to some exemplary embodiments ofthe present application;

FIG. 2 is a schematic top view of a motion device for virtual realityinteraction according to some exemplary embodiments of the presentapplication;

FIG. 3 is an enlarged partial view of III in FIG. 1, schematicallyshowing structures and arrangement of sockets and second balls in a coreaccording to some exemplary embodiments of the present application;

FIG. 4 is a schematic bottom view of a running belt unit in a retractedstate and a stretched state according to some exemplary embodiments ofthe present application;

FIG. 5 is a schematic bottom view of a groove and an elastic strap whenthe running belt unit is in a retracted state and a stretched stateaccording to some exemplary embodiments of the present application;

FIG. 6 is a schematic top view of three adjacent running belt units in aretracted state and a stretched state according to some exemplaryembodiments of the present application.

FIG. 7 is a schematic bottom view of three adjacent running belt unitsin a retracted state and a stretched state according to some exemplaryembodiments of the present application.

FIG. 8 is a schematic view of a two-dimensional coordinate system ofsome exemplary embodiments of the application;

FIG. 9 is a schematic view of a three-dimensional real-time coordinatesystem according to some exemplary embodiments of the presentapplication;

FIG. 10 is a view showing an example of calculating a barycentercoordinate through a triangular approximation algorithm according tosome exemplary embodiments of the present application;

FIG. 11 is a schematic view of a relationship between a user jumpingheight and a horizontal displacement according to some exemplaryembodiments of the present application.

DETAILED DESCRIPTION

Some exemplary embodiments of the present application are described indetail below, examples of which are illustrated in the accompanyingdrawings, wherein the same or similar reference numerals refer to thesame or similar elements or elements having the same or similarfunctions throughout. The embodiments described below by referring tothe drawings are exemplary and are intended to explain the presentapplication and should not be construed as limiting the application.

At present, when a virtual reality motion device realizes an interactionbetween virtuality and reality through motions of lower limbs of a user,the user's experience through the mode of realizing the interactionbetween the virtuality and the reality is very poor due to limitedmotion range of the lower limbs of the user. In related art,omni-directional (all-directional, universal) motion experiences arerealized through omni-directional wheels with generally complexstructures, which is poor in practical operability.

In some exemplary embodiments of the present disclosure, a motion devicefor virtual reality interaction, hereinafter referred to as a motiondevice for short, is proposed to solve the technical problems that thevirtual reality motion device in the related art has poor userexperience due to the limited motion range of the user's lower limbs,and the device capable of realizing motion experience has complexstructure and poor actual operability.

First, with reference to FIGS. 1-7, a structure of a motion device forvirtual reality interaction according to some exemplary embodiments ofthe present application will be described.

FIG. 1 is a schematic cross-sectional view of a motion device forvirtual reality interaction according to some exemplary embodiments ofthe present application. FIG. 2 is a schematic top view of a motiondevice for virtual reality interaction according to some exemplaryembodiments of the present application. FIG. 3 is a schematic viewshowing structures and arrangement of sockets and second balls of a coreaccording to some exemplary embodiments of the present application. FIG.4 is a bottom view of a running belt unit in a retracted state and astretched state according to some exemplary embodiments of the presentapplication.

As shown in FIGS. 1-4, the motion device includes a running belt 1, acore 2 supporting the running belt 1, and a frame 4 carrying the runningbelt 1 and the core 2.

The running belt 1 is configured to wrap the core 2 and capable ofsliding on the outer surface of the core 2, wherein the running beltcomprises a plurality of running belt units 11, each running belt unit11 is provided with a plurality of grooves 12 on the surface facing thecore 2, and each groove 12 of each running belt unit 11 is connectedwith a corresponding groove 12 of an adjacent running belt unit 11through an elastic strap 13. The frame 4 is located at a periphery ofthe running belt 1 and is configured to carry the running belt 1 and thecore 2, wherein a plurality of first balls 5 are arranged between theframe 4 and the running belt 1. Therefore, a user can realizeomni-directional movements on the motion device, and the motion devicehas simple structure, excellent practical operability and improved userexperience.

The core 2 is substantially ellipsoidal, and the ellipsoid has twoopposite substantially planar main surfaces and an arc surfaceconnecting the two main surfaces. The outer surface of the core 2 isprovided with a plurality of sockets 31, and a second ball 32 isarranged in each socket 31. The plurality of sockets 31 are positionedin the surface of the core 2 contacting the omni-directional runningbelt 1, and a plurality of second balls 32 are respectively arranged ina plurality of sockets 31, so that the user can more smoothly realizeomni-directional movements on the motion device. Therefore, the motiondevice comprising the sockets-balls has a simple structure, excellentpractical operability and improved user experience.

As shown in FIG. 2, specifically, the shape of the omni-directionalrunning belt 1 in a top view may be circular. In addition, the runningbelt unit 11 can be made of ultra-light metal material or otherultra-light material that is less susceptible to wear. The core is madeof rigid material or hard material. The elastic strap is a metal elasticstrap. The first ball and the second ball are both metal balls. Thecross-sectional shape of each running belt unit 11 may be hexagonal, ormay be square, circular or any other arbitrary shape, and thisapplication is not limited to this.

In some exemplary embodiments, when the cross-sectional shape of therunning belt unit 11 has a hexagonal shape (hereinafter referred to as“the running belt unit is hexagonal” for short), a corresponding grooveis provided along a perpendicular bisector of each side of the hexagon.The side length of the hexagon can be arbitrarily set as required. Forexample, the side length of the running belt unit 11 may be set to be 1cm or less according to the actual size of the omni-directional runningbelt 1. It should be noted that in practical application, the sidelength of the running belt unit 11 when it is hexagonal should not bemore than 2 cm.

In addition, the upper surface of the running belt unit 11 may have asawtooth structure, so that when the user moves on the omni-directionalrunning belt 1, friction between the omni-directional running belt 1 andthe user's feet can be increased to prevent the user from slipping. Thesurface of the running belt unit 11 facing the core may be smooth andcoated with lubricating oil, so that friction between the running belt 1and the core 2 can be reduced when this surface contacts with the secondballs 32 on the surface of the core 2.

In some exemplary embodiments, an upper surface and a lower surface ofthe core 2 may be planar, thereby more conforming to a scene of a usermoving on the ground. In addition, the core 2 may be a hard solidsubstantially in the shape of an ellipsoid, and its material is notlimited but needs to have ultra-strong hardness. The surface of thesocket 31 of the core 2 is a smooth surface, and the surface of the core2 other than the sockets 31 may be rougher than the surface of thesocket 31. For example, the roughness of the surface of the core 2 otherthan the sockets 31 is 5 micrometers (um) or less.

As shown in FIG. 3, the plurality of sockets 31 may be arranged inequilateral triangles, that is, connecting lines between centers ofthree adjacent sockets 31 take on an equilateral triangular shape. Thesecond ball 32 may be made of metal material, and a lubricating oil 33may be coated between the second ball 32 and the socket 31. The size ofthe socket 31 in the surface of the core 2, the spacing size between thesockets 31, and the like can be set as required. For example, in someexemplary embodiments of the present application, a diameter of thesocket 31 may be set to be less than 0.5 cm, and the spacing between thetwo adjacent sockets 31 (i.e., a minimum width of the spacing areabetween the two adjacent sockets) may be set to be less than or equal to0.25 cm, so that in any case, each running belt unit 11 is supported byat least two second balls 32 to ensure that the edge of the running beltunit 11 is not stuck by the second balls 32. In some exemplaryembodiments of the present application, the socket 31 may be an embeddedsocket, for example, the socket 31 has a spherical segment shape, aheight of the spherical segment is ⅘ of a height of the sphere, and adiameter of the second ball 32 in the socket 31 is less than 0.4 cm. Thesocket 31 and the second ball 32 are respectively formed so that thesecond ball 32 is embedded in the middle of the socket 31, and there isno obvious relative displacement between the second ball 32 and thesocket 31 (i.e., the gap between the two should not be too large), solong as the second ball 32 can rotate smoothly in the socket 31. Theomni-directional running belt 1 generates rolling friction through thesecond balls 32 on the surface of the core 2 and with the help of thelubricating oil 33, the friction force between the omni-directionalrunning belt 1 and the core 2 can be reduced.

In some exemplary embodiments, the elastic strap 13 may be made of metalthat can be stretched and retracted quickly. As shown in FIG. 4, thesides of each running belt unit 11 facing the core are provided withgrooves 12, each groove 12 is perpendicular to each corresponding sideof the running belt unit 11, and the elastic straps 13 are installed inthe grooves 12. Two adjacent running belt units 11 share an elasticstrap 13, and the length of the elastic strap 13 can be smaller than thedistance between two opposite sides of the running belt unit 11.

Further, as shown in FIGS. 5-7, assuming that the first running beltunit 110 and the second running belt unit 111 are two adjacent runningbelt units in the omni-directional running belt 1, the first runningbelt unit 110 has a first stop wall 140 and a first groove 120, thefirst groove 120 has a first slide rail 150; the second running beltunit 111 has a second stop wall 141 and a second groove 121, the secondgroove 121 has a second slide rail 151. The elastic strap 13 has a firstT-shaped end 130 and a second T-shaped end 131. The first T-shaped end130 can slide in the first slide rail 150 and stop at the first stopwall 140. The second T-shaped end 131 can slide in the second slide rail151 and stop at the second stop wall 141.

Specifically, the first stop wall 140 is disposed at the bottom of thefirst groove 120, the second stop wall 141 is disposed at the bottom ofthe second groove 121, and both ends of the elastic strap 13 arerespectively T-shaped, so that when the omni-directional running belt 1is in the stretched state, the elastic strap 13 will not break away fromthe groove due to excessive pulling force.

Further, as shown in FIG. 1, the motion device may further include aframe 4 carrying the omni-directional running belt 1 and the core 2. Theplurality of first balls 5 are arranged between the frame 4 and theomni-directional running belt 1. The sizes of the first balls 5 may bedifferent to conform to or follow the size of the spacing between theframe 4 and the running belt 1. The first balls 5 may be sandwichedbetween the frame 4 and the running belt 1 or may be mounted on theinner surface of the frame 4 so that it can only rotate but nottranslate relative to the frame 4.

As shown in FIG. 1, the first balls 5 with different sizes aresandwiched between the frame 4 and the omni-directional running belt 1and can rotate with the movement of the omni-directional running belt 1,thereby assisting the movement of the omni-directional running belt 1 onthe surface of the core 2. The frame 4 cooperates with the first balls 5to support the omni-directional running belt 1 and the core 2.

As shown in FIG. 6, when in a horizontal state, the running belt unit 11of the omni-directional running belt 1 assumes a retracted state on theupper and lower horizontal planes, and there is no gap between adjacentrunning belt units 11. The omni-directional running belt 1 is moved bythe friction of the user's sole. When the running belt unit 11 moves tothe vicinity of the frame 4, the elastic straps 13 between the runningbelt units 11 are stretched to assist the deformation of theomni-directional running belt 1 with the change of the shape of the core2, thereby reducing damage to the omni-directional running belt 1. Theedge of the core 2 adjacent to the frame 4 may be cambered so as toprevent abrasion of the running belt unit 11 and the elastic strap 13.

In addition, the frame 4 can be set higher than the upper surface of theomni-directional running belt 1, thereby reminding the user of theposition of the edge of the omni-directional running belt 1 andpreventing the user from falling.

Further, as shown in FIG. 1, the motion device may further include abrush 41 disposed on the frame 4, the brush 41 being adjacent to anouter periphery of the main surface of the core 2. The brush 41 isinstalled at a gap between the upper frame 4 and the omni-directionalrunning belt 1, so as to prevent foreign matters from entering the gapbetween the omni-directional running belt 1 and the frame 4 and damagingthe motion device.

Further, an oil pipe and an oil brushing device connected to the oilpipe may be provided in the frame 4, so that the lubricating oil can bereplenished into the socket 31 in the surface of the core 2 through agap when the running belt unit 11 is stretched. The oil pipe isconnected with an oil source, and the oil brushing device comprises anoil supply head, wherein the oil supply head is configured to supply oilto the socket through the gap when the gap occurs between two adjacentrunning belt units. For example, the oil supply head includes an oilbrush to brush oil toward the socket and the second ball.

Further, in some exemplary embodiments of the present application, theside (or surface) of each running belt unit 11 facing the core isprovided with a pressure sensor to sense the pressure of the user's footwhen the user moves on the motion device, thereby determining theposition of the user's actual (real) foot falling point, and determininga speed, distance, direction, etc. of the user's movement according tothe position of the actual foot falling point. According to the speed,distance and direction of the user's movement in reality, the user'sposition and moving direction in the virtual scene can be determined toachieve better interaction between reality and virtuality. The pressuresensor may be provided in the middle of the running belt unit 11.

Next, with reference to FIGS. 8-11, the process and principle of how themotion device for virtual reality interaction realizes the interactionbetween virtuality and reality will be explained.

Specifically, some exemplary embodiments of the present applicationprovide a virtual reality system that includes a virtual reality deviceand a motion device for virtual reality interaction.

The virtual reality device includes a receiver and a processor.

The motion device for virtual reality interaction comprises a core; arunning belt carried by the core, the running belt configured to wrapthe core and capable of sliding on the outer surface of the core,wherein the running belt comprises a plurality of running belt units, asurface of each running belt unit facing the core is provided with aplurality of grooves, each groove of each running belt unit is connectedwith a corresponding groove of an adjacent running belt unit through anelastic strap, and the surface of each running belt unit facing the coreis further provided with a pressure sensor; a frame located at aperiphery of the running belt and configured to carry the running beltand the core, wherein a plurality of first balls are arranged betweenthe frame and the running belt; and a transmitter configured to transmitmotion data of a user on the running belt to the receiver of the virtualreality device. The processor is configured to establish atwo-dimensional coordinate system according to the pressure sensordistribution of the running belt, and combine the two-dimensionalcoordinate system with a virtual scene to create a three-dimensionalreal-time coordinate system.

Of course, the processor is not limited to being provided on the virtualreality device, but may be alternatively or additionally provided on themotion device for virtual reality interaction, and may also be providedoutside the virtual reality device and the motion device for virtualreality interaction. The transmitter is not limited to only beingprovided on the motion device for virtual reality interaction. Forexample, the virtual reality device may also be provided with atransmitter to send data to the motion device and/or the processor forvirtual reality interaction so as to better realize the interaction. Thereceiver is not limited to only being provided on the virtual realitydevice. For example, the receiver may also be provided on the motiondevice for virtual reality interaction to receive data from the virtualreality device so as to better realize interaction.

When the processor is arranged on the motion device for virtual realityinteraction, data processing is carried out through the processor on themotion device to realize interaction between virtuality and reality.When the processor is provided on the virtual reality device, dataprocessing is carried out through the processor on the virtual realitydevice to realize interaction between virtuality and reality. Forexample, when the virtual reality device is provided with the processor,the motion device for virtual reality interaction is provided with thetransmitter, and the virtual reality device is provided with thereceiver, the motion device for virtual reality interaction isconfigured to sense a user's motion through the pressure sensors of therunning belt, and generate motion data; transmit the motion data of theuser to the receiver of the virtual reality device through thetransmitter. The virtual reality device is configured to process theuser motion data received by the receiver through the processor; displaya virtual scene image; and adjust the virtual scene image according tothe result of the motion data processing by the processor.

As an example, each running belt unit 11 of the omni-directional runningbelt 1 includes a pressure sensor on the surface facing the core, sothat a sensor array can be formed on the entire omni-directional runningbelt 1. In some exemplary embodiments of the present application, atwo-dimensional coordinate system may be established according to thesensor distribution in the motion area on the omni-directional runningbelt 1, and a three-dimensional real-time coordinate system may becreated according to the two-dimensional coordinate system and thevirtual scene.

Specifically, as shown in FIG. 8, after the motion device is turned on,the processor can mark the sensor closest to the center of the motionarea as (x0, y0) according to the sensor distribution in the motion areaon the omni-directional running belt 1, and then automatically assigntwo-dimensional coordinate values (x, y) corresponding to all sensors onthe surface of the omni-directional running belt 1 with (x0, y0) as thecenter point according to the coordinate direction shown in FIG. 8 toestablish a two-dimensional coordinate system. Since the surface of theomni-directional running belt 1 is completely closed, the coordinatevalues corresponding to all sensors can be located in the first quadrantof the two-dimensional coordinate system by curved surface extension ofthe coordinate system.

In some exemplary embodiments of the present application, assuming thatthe number of sensors distributed along a single coordinate axisdirection is in and n, respectively, the coordinates along the x-axis inthe two-dimensional coordinate system may be (x0, y0) . . . (xm−1, y0)sequentially, and the coordinates along the y-axis in thetwo-dimensional coordinate system may be (x0, y0) . . . (x0, yn−1)sequentially. In this way, initial coordinate values in thetwo-dimensional coordinate system can be obtained.

Further, it can be understood that in the virtual scene, there may besome terrains, such as houses, hills, cliffs, etc. that cannot bedirectly walked over. Therefore, according to continuous changes of thevirtual scene and a correspondence relationship between the motion areaand the virtual scene, each sensor needs to add a three-dimensionalcoordinate parameter z on the basis of the two-dimensional coordinatesystem. The combination of this parameter and the two-dimensionalcoordinate in the two-dimensional coordinate system can be changed inreal time according to the changes of the terrains in the virtual scene,thus forming a three-dimensional coordinate values (x, y, z) for eachtwo-dimensional coordinate point, as shown in FIG. 9.

In specific implementation, when the user's feet stand on the motionarea of the omni-directional running belt 1, a pressure sensordistribution area as shown in FIG. 10 will be generated in the motionarea. In some exemplary embodiments of the present application, afterthe user stands on the motion area, a three-dimensional real-timecoordinate system can be initialized according to the user's initialbarycenter coordinate on the omni-directional running belt 1 and thevirtual scene. The three-dimensional real-time coordinate systemincludes a correspondence relationship between actual coordinates (i.e.,coordinates corresponding to each sensor on the omni-directional runningbelt 1, which includes three directions of x, y and z) and scenecoordinates (i.e., coordinates in the virtual scene, which includesthree directions of x, y and z). In some exemplary embodiments of thepresent application, initializing the three-dimensional real-timecoordinate system specifically includes initializing the correspondencerelationship between the actual coordinates and the scene coordinates inthe three-dimensional real-time coordinate system.

In some exemplary embodiments, the initial barycenter coordinate of theuser on the omni-directional running belt 1 may be determined in thefollowing manner.

First, the pressure sensors in the area where the user's feet arelocated can be connected in the manner shown in FIG. 10 to divide thearea into a plurality of triangles. Assuming that coordinates of threevertices of a triangle A are (x1, y1), (x2, y2), (x3, y3) respectively,a barycenter coordinate Gg1(Xg1, Yg1) of the triangle A can bedetermined according to the following formulas (1) and (2):

Xg1=(x1+x2+x3)/3  (1)

Yg1=(y1+y2+y3)/3  (2)

Then, according to formula (3), an area of the triangle A is determined.

S1=((x2−x1)*(y3−y1)−(x3−x1)*(y2−y1))/2  (3)

Then the barycenter coordinate and the area of each triangle in the areawhere the user's feet are located are calculated by the above method,and finally initial barycenter coordinates of the feet are calculatedrespectively according to the above calculation results.

Specifically, assuming that the area where the user's left foot islocated can be divided into m triangles, the initial barycentercoordinate Gg(Xg, Yg) of the left foot can be calculated according toformulas (4) and (5):

$\begin{matrix}{{Xg} = {\frac{D{\int{\int{xdS}}}}{S} = \frac{\sum\limits_{i = 1}^{m}{XiSi}}{\sum\limits_{i = 1}^{m}{Si}}}} & (4) \\{{Yg} = {\frac{D{\int{\int{ydS}}}}{S} = \frac{\sum\limits_{i = 1}^{m}{YiSi}}{\sum\limits_{i = 1}^{m}{Si}}}} & (5)\end{matrix}$

In the formulas, Xi is an x-axis coordinate value of an i-th triangle,Yi is a y-axis coordinate value of the i-th triangle, and Si is an areaof the i-th triangle.

It should be noted that the calculation method of the initial barycentercoordinate of the user's right foot is the same as the calculationmethod of the initial barycenter coordinate of the left foot, and willnot be repeated here.

In addition, in practical application, when determining the initialbarycenter coordinate of the user on the omni-directional running beltby the above-mentioned method, as shown in FIG. 10, there may be asituation where one or two vertices of some triangles are not in thearea where the foot is located. In order to improve the accuracy ofdetermining the barycenter coordinate, in some exemplary embodiments ofthe present application, triangles with one or two vertices not in thearea where the foot is located may be discarded, and the initialbarycenter coordinates may be calculated only based on triangles withall three vertices in the area where the foot is located.

Therefore, the initial barycenter coordinate of the user on theomni-directional running belt 1 can be determined through the abovetriangular approximation algorithm, and then the correspondencerelationship between the actual coordinates and the scene coordinates inthe three-dimensional real-time coordinate system can be set accordingto the initial barycenter coordinate. For example, assuming that theinitial barycenter coordinate of the user on the omni-directionalrunning belt 1 is (Xg, Yg) and a scene coordinate of an area B on a flatground in the virtual scene is (Xt, Yt), the coordinate (Xg, Yg) can beset to correspond to the scene coordinate (Xt, Yt) so that the userstands on the flat ground area B in the virtual scene.

It can be understood that since the actual number of sensors on theomni-directional running belt 1 is much larger than that shown in FIG.10, the area of the region where the user's feet are located and theinitial barycenter coordinate of the user calculated by theabove-mentioned method are close to the real values, thus meeting thebarycenter accuracy requirements.

Further, after initializing the three-dimensional real-time coordinatesystem in the above manner, the user's position and moving direction inthe virtual scene can be determined according to the user's movement onthe omni-directional running belt 1 when the user moves, and thecorrespondence relationship between the actual coordinates and the scenecoordinates in the three-dimensional real-time coordinate system can beupdated according to the user's movement.

Specifically, a movement state of the user can be determined accordingto pressure changes received by the pressure sensors corresponding tothe barycenter coordinates of the user's feet, such as whether the useris walking or jumping, etc., and then the position and moving directionof the user in the virtual scene under different movement states can bedetermined. The barycenter coordinates of both feet during the user'smovement can be determined according to the above-mentioned triangleapproximation algorithm, which is not repeated here.

In some exemplary embodiments, if it is determined that the user firstlifts the left foot or the right foot and then falls the left foot orthe right foot according to the pressure changes received by thepressure sensors corresponding to the barycenter coordinates of theuser's feet, then it can be determined that the user is walking, so thatactual coordinates of starting points and falling points of the user'sfeet can be determined according to the pressure changes received by thepressure sensors corresponding to the barycenter coordinates of theuser's feet. A walking direction and a walking distance of the user inthe virtual scene are determined according to the actual coordinates ofthe starting points and the falling points of the user's feet and thecorrespondence relationship between the actual coordinates and the scenecoordinates, and a walking speed of the user in the virtual scene isdetermined according to the walking distance and an time intervalbetween the starting point and the falling point of each step.

In some exemplary embodiments, it may be determined that the user isjumping if the pressures received by the pressure sensors correspondingto the barycenter coordinates of the user's feet suddenly disappearssimultaneously. When the user jumps, if there is an obstacle higher thana horizontal level at the scene coordinates in the virtual scenecorresponding to the barycenter coordinates of the user's feet (the Zvalue of the actual coordinate corresponding to the obstacle is greaterthan 0), the user may jump over or jump on the obstacle in a jumpingmanner. At this time, the processor needs to judge whether a jumpingheight and horizontal displacement of the user meet requirements so asto judge whether the user can pass over the obstacle in the virtualscene.

Specifically, when the user stands on the omni-directional running belt1, the processor can determine a mass or weight of the user according tothe pressure values received by the pressure sensors corresponding tothe barycenter coordinates of the user's feet, so that when the userjumps, the processor can determine a maximum pressure value F receivedby the pressure sensors according to the pressure changes received bythe pressure sensors corresponding to the barycenter coordinates of theuser's feet, and calculate an initial acceleration a of the useraccording to formula (6) based on the mass in of the user's body and themaximum pressure value F:

F=ma  (6)

Then, according to the time interval t between two adjacent landings ofthe user and the initial acceleration a, the jumping height h of theuser is calculated according to formula (7):

H=½at ²  (7)

According to the left foot barycenter coordinate G1(X_(g1), Y_(g1)) andright foot barycenter coordinate G2(X_(g2), Y_(g2)) before the user'sfeet leave the ground, and the left foot barycenter coordinateG1′(X_(g′1), Y_(g′1)) and the right foot barycenter coordinateG2′(X_(g′2), Y_(g′2)) after landing, the horizontal displacement L ofthe user, that is, the jumping distance of the user, is determinedaccording to formula (8):

$\begin{matrix}{L = \sqrt{\left( {\frac{\left( {X_{g1} + X_{g2}} \right)}{2} - \frac{\left( {X_{g^{\prime}1} + X_{g^{\prime}2}} \right)}{2}} \right)^{2} + \left( {\frac{\left( {Y_{g1} + Y_{g2}} \right)}{2} - \frac{\left( {Y_{g^{\prime}1} + Y_{g^{\prime}2}} \right)}{2}} \right)^{2}}} & (8)\end{matrix}$

It should be noted that the determined jumping height and horizontaldisplacement of the user are the actual jumping height and horizontaldisplacement of the user on the omni-directional running belt 1. In someexemplary embodiments of the present application, after determining theactual jumping height and horizontal displacement of the user, thejumping height and horizontal displacement of the user in the virtualscene can be determined according to the correspondence relationshipbetween the actual coordinates and the scene coordinates, and thenwhether the jumping height and horizontal displacement are greater thanthe height and horizontal dimension of the obstacle in the virtual scenecan be determined; if not, it can be determined that the user has notjumped over the obstacle, the horizontal displacement in the virtualscene can be zeroed, and the correspondence relationship between thescene coordinates and the actual coordinates can be updated.

In some exemplary embodiments, when the user jumps, if there is anobstacle lower than the horizontal level at the scene coordinates in thevirtual scene corresponding to the barycenter coordinates of the user'sfeet (the Z value of the actual coordinate corresponding to the obstacleis less than 0), that is, there may be a river or ravine in front of theuser in the virtual scene, and the user may jump over the obstacle in ajumping manner. At this time, the processor needs to determine whetherthe horizontal displacement of the user's jump meets the requirements soas to determine whether the user can pass over the obstacle in thevirtual scene.

Specifically, if the Z value of the scene coordinate corresponding tothe barycenter coordinate when the user lands on both feet is greaterthan or equal to 0, and there is no steep slope with a height exceedinga certain threshold in front of the user in the virtual scene, it can bedetermined that the user has passed over the obstacle, otherwise, it canbe determined that the user has not passed over the obstacle.

It can be understood that when an obstacle with a height exceeding acertain threshold exists in front of the user in the virtual scene, andthe user hasn't passed over the obstacle, if the user continues to moveon the omni-directional running belt 1, the actual coordinatescorresponding to the barycenter coordinates of the user's feet willcontinue to change, but the position of the user in the virtual scenewill not change. At this time, the scene coordinate values of the X andY axes of the user in the current scene can be given to the continuouslychanging actual coordinates of the user's feet in real time, while theheight values of all sensors in front will remain unchanged, and theuser is prompted to turn. If the user turns, the scene change isre-matched with the user's movement, thus realizing synchronous changeof the actual coordinates at the user's feet and the scene coordinates.The threshold can be set according to the height that the user cannotnormally pass over. For example, if the minimum height that the usercannot normally pass over is 0.5 meters, the threshold can be set to 0.5meter.

In addition, it can be understood that when determining the barycentercoordinates of the user's feet in some exemplary embodiments of thepresent application, a certain error exists because the calculation isonly based on triangles whose three vertices are all in the area wherethe user's feet are located. Therefore, when the user moves for a longtime, especially when walking for a long distance in the same direction,the problem of error accumulation is likely to occur, resulting ininaccurate moving distance of the user determined by the processor.

In order to avoid inaccuracy of the determined moving distance of theuser due to error accumulation, the application introduces a real-timeerror elimination mechanism. Specifically, when the motion device isturned on and initialized, a typical virtual scene, such as a flatground scene, can be set, and the user is prompted to take a few stepson a trial basis, so that a corresponding error adjustment parameter iscalculated according to the walking steps and speeds of the user in thetrial walking process in the typical virtual scene, and further, in themotion process of the user, the distance the user moves in the virtualscene is adjusted according to the error adjustment parameter for eachstep, thereby eliminating accumulated errors.

Specifically, the distance that the user moves in each step can beadjusted by the following formula (9):

s=√{square root over ((x1−x0)²+(y1−y0)²)}+∂  (9)

In the formula, s is the distance the user moves in a certain step inthe virtual scene, ∂ is the error adjustment parameter, (x1, y1) is thefalling point coordinate of the user in a certain step in the virtualscene, and (x0, y0) is the starting point coordinate of the user in acertain step in the virtual scene.

It can be understood that by calculating different error adjustmentparameters according to different steps and speeds of different users ineach typical virtual scene, and adjusting the jumping distances orwalking distances in the corresponding scene according to thecorresponding error adjustment parameters in the motion process ofdifferent users, the accumulated errors of different users in the motionprocess in corresponding virtual scenes can be eliminated pertinently,so that the determined moving distances of different users in the motionprocess in corresponding virtual scenes are more accurate.

According to the motion device for virtual reality interaction providedby some exemplary embodiments of the application, a plurality of runningbelt units are connected by grooves and elastic straps to form anomni-directional running belt, the omni-directional running belt issupported by a core, and a plurality of second balls are respectivelyarranged in a plurality of sockets in a surface of the core contactingthe omni-directional running belt, so that a user can move in anydirection on the motion device. The motion device has a simple structureand excellent actual operability. Moreover, by arranging a pressuresensor on one side of each running belt unit facing the core, creating athree-dimensional real-time coordinate system, and updating thethree-dimensional real-time coordinate system in real time according tothe movement of the user, a real-time correspondence relationshipbetween relative position changes of the pressure sensors and thethree-dimensional coordinate system in the virtual scene is realized,and finally the interactive process between the omni-directional runningbelt and a virtual reality device such as a computer is completed, whichresults a richer and more vivid user experience.

The virtual reality system provided by some exemplary embodiments of thepresent application aims to solve the technical problems that thevirtual reality system in related art has poor user experience due tolimited motion range of lower limbs of a user, and devices capable ofrealizing omni-directional motion experience have complex structure andpoor actual operability. The virtual reality system includes the motiondevice for virtual reality interaction described in the aboveembodiments, hereinafter referred to as the motion device for short, andthe virtual reality device.

The explanation of the structure and implementation principle of themotion device can refer to the detailed description of some exemplaryembodiments described above, which will not be described in detailbelow.

The virtual reality device in some exemplary embodiments of the presentapplication may be any device capable of displaying a virtual scene,such as computers, smart phones, wearable devices, head-mounteddisplays, etc.

In some exemplary embodiments, the motion device can sense the motion ofthe user through the omni-directional running belt included in themotion device, and generate motion data of the user in the mannerdescribed in some exemplary embodiments above, wherein the motion datacan be at least one of walking distance, walking speed, walkingdirection, jumping height, initial acceleration and horizontaldisplacement of the user in a virtual scene, and then send the motiondata of the user to the virtual reality device, so that the virtualreality device can adjust the virtual scene image according to themotion data of the user.

For example, assuming that in the current scene image displayed in thevirtual reality device, the user is at position 1, and when the usermoves on the omni-directional running belt, the motion device forvirtual reality interaction determines that the user walked 1 meter in adirection A and moved to a position 2 in the virtual scene through theuser motion sensed by the omni-directional running belt, then the motiondirection and walking distance of the user can be transmitted to thevirtual reality device, so that the virtual reality device can adjustthe current virtual scene image to be the scene image of the user atposition 2 according to the user motion data.

In addition, in order for the motion device to initialize thethree-dimensional real-time coordinate system according to the user'sinitial barycenter coordinate and the virtual scene when the user standson the omni-directional running belt, in some exemplary embodiments ofthe present application, the motion device can also send a message tothe virtual reality device when the user stands on the omni-directionalrunning belt, so that the virtual reality device can send an initiallydisplayed virtual scene image to the motion device, so that the motiondevice initializes the three-dimensional real-time coordinate systemaccording to the user's initial barycenter coordinate and the initiallydisplayed virtual scene image.

The initially displayed virtual scene image can be set as required. Forexample, when the virtual reality system is used to play a game, theinitially displayed virtual scene image may be an image of a virtualuser in the game interface when the game starts. Alternatively, it maybe a virtual scene image displayed at the time when the last gameexited, etc.

It should be noted that in some of the above exemplary embodiments ofthe present application, it is exemplarily illustrated that the motiondata of the user in the virtual scene is generated by the motion deviceaccording to the motion of the user. In actual application, after theomni-directional running belt senses the motion of the user, the motiondevice can also send the sensing result to the virtual reality device,so that the motion data of the user in the virtual scene is determinedby the processor in the virtual reality device, and then the virtualscene image is adjusted.

The virtual reality system provided by some exemplary embodiments of thepresent application includes a virtual reality device and a motiondevice for virtual reality interaction. Through the interaction betweenthe virtual reality device and the motion device for virtual realityinteraction, the virtual scene image is synchronously displayed in thevirtual reality device when the user moves on the motion device forvirtual reality interaction, thus realizing the interaction betweenvirtuality and reality.

In the description of this specification, the description referring toterms “one embodiment,” “some embodiments,” “examples,” “specificexamples,” or “some examples” and the like means that a specificfeature, structure, material, or characteristic described in connectionwith the embodiment or example is included in at least one embodiment orexample of this application.

Furthermore, the terms “first” and “second” are used for descriptivepurposes only and cannot be understood as indicating or implyingrelative importance or implicitly indicating the number of technicalfeatures indicated. Thus, features defined by “first” and “second” mayexplicitly or implicitly include at least one of the features.

Any process or method description in the flowchart or otherwisedescribed herein can be understood as representing a module, segment, orportion of code including one or more executable instructions forimplementing specific logical functions or steps of the process, and thescope of preferred embodiments of the present application includesadditional implementations in which functions may be performed in anorder other than that shown or discussed, including a substantiallysimultaneous manner or the reverse order according to the functionsinvolved, which should be understood by those skilled in the art towhich embodiments of the present application belong.

It should be understood that various parts of the present applicationmay be implemented in hardware, software, firmware, or a combinationthereof. In the above embodiments, the plurality of steps or methods maybe implemented in software or firmware stored in a memory and executedby a suitable instruction execution system. For example, if implementedin hardware, as in another embodiment, it may be implemented by any oneor a combination of the following technologies known in the art:discrete logic circuits having logic gates for implementing logicfunctions on data signals, application specific integrated circuitshaving appropriate combinational logic gates, programmable gate arrays(PGA), field programmable gate arrays (FPGA), etc.

One of ordinary skill in the art can understand that all or part of thesteps carried by the method for implementing the above embodiment can becompleted by instructing relevant hardware through a program, which canbe stored in a computer readable storage medium, and the program, whenexecuted, includes one or a combination of the steps of the methodembodiments.

The storage medium mentioned above may be read-only memory, magneticdisk or optical disk, etc. Although the embodiments of the presentapplication have been shown and described above, it is to be understoodthat the above-mentioned embodiments are exemplary and should not beconstrued as limiting the present application, and those of ordinaryskill in the art may make changes, modifications, substitutions andvariations to the above-mentioned embodiments within the scope of thepresent application.

1. A motion device for a virtual reality interaction, comprising: acore; a running belt carried by the core, wherein the running belt isconfigured to wrap the core and capable of sliding on an outer surfaceof the core, the running belt comprises a plurality of running beltunits, a surface of each running belt unit facing the core is providedwith a plurality of grooves, and each groove of each running belt unitis connected with a corresponding groove of an adjacent running beltunit through an elastic strap; and a frame located at a periphery of therunning belt and configured to carry the running belt and the core,wherein a plurality of first balls are arranged between the frame andthe running belt.
 2. The motion device for the virtual realityinteraction according to claim 1, wherein the outer surface of the coreis provided with a plurality of sockets, and a second ball is arrangedin each socket.
 3. The motion device for the virtual reality interactionaccording to claim 1, wherein a cross section of each running belt unitis hexagonal, and a corresponding groove is provided along aperpendicular bisector of each side of the hexagon.
 4. The motion devicefor the virtual reality interaction according to claim 1, wherein therunning belt is an omni-directional running belt and comprises adjacentfirst and second running belt units, the first running belt unit has afirst stop wall and a first groove, the first groove has a first sliderail, the second running belt unit has a second stop wall and a secondgroove, the second groove has a second slide rail, the elastic strap hasa first T-shaped end and a second T-shaped end, the first T-shaped endis configured to slide in the first slide rail and stop at the firststop wall, and the second T-shaped end is configured to slide in thesecond slide rail and stop at the second stop wall.
 5. The motion devicefor the virtual reality interaction according to claim 1, wherein thecore is substantially ellipsoidal, and the ellipsoid has two oppositesubstantially planar main surfaces and an arc surface connecting the twomain surfaces.
 6. The motion device for the virtual reality interactionaccording to claim 1, wherein the core is made of rigid material, eachrunning belt unit is made of a light metal material, the elastic strapis a metal elastic strap, and the first balls and the second balls areboth metal balls.
 7. The motion device for the virtual realityinteraction according to claim 2, wherein as to the plurality ofsockets, connecting lines between centers of adjacent three sockets takeon an equilateral triangular shape.
 8. The motion device for the virtualreality interaction according to claim 2, wherein each socket has aspherical segment shape, and a height of the spherical segment is ⅘ of aheight of the sphere.
 9. The motion device for the virtual realityinteraction according to claim 5, wherein the frame is provided with abrush adjacent to an outer periphery of one of the main surfaces. 10.The motion device for the virtual reality interaction according to claim1, wherein the surface of each running belt unit facing the core isfurther provided with a pressure sensor.
 11. The motion device for thevirtual reality interaction according to claim 2, wherein the framecomprises an oil supply pipeline and an oil supply head arrangedtherein, the oil supply pipeline is connected with an oil source, andthe oil supply head is configured to supply oil to the socket through agap when the gap occurs between two adjacent running belt units.
 12. Avirtual reality system comprising: a virtual reality device comprising areceiver and a processor; and a motion device for a virtual realityinteraction comprising: a core; a running belt carried by the core,wherein the running belt is configured to wrap the core and capable ofsliding on an outer surface of the core, the running belt comprises aplurality of running belt units, a surface of each running belt unitfacing the core is provided with a plurality of grooves, each groove ofeach running belt unit is connected with a corresponding groove of anadjacent running belt unit through an elastic strap, and the surface ofeach running belt unit facing the core is further provided with apressure sensor; a frame located at a periphery of the running belt andconfigured to carry the running belt and the core, wherein a pluralityof first balls are arranged between the frame and the running belt; anda transmitter configured to transmit motion data of a user on therunning belt to the receiver of the virtual reality device, wherein theprocessor is configured to establish a two-dimensional coordinate systemaccording to a distribution of the pressure sensor of the running belt,and combine the two-dimensional coordinate system with a virtual sceneto create a three-dimensional real-time coordinate system.
 13. Thevirtual reality system according to claim 12, wherein the processor isfurther configured to: initialize the three-dimensional real-timecoordinate system according to an initial barycenter coordinate of theuser on the running belt and the virtual scene, wherein thethree-dimensional real-time coordinate system comprises a correspondencerelationship between actual coordinates and scene coordinates; andupdate the correspondence according to a movement of the user.
 14. Thevirtual reality system according to claim 13, wherein the processor isfurther configured to: determine actual coordinates of starting pointsand falling points of the user's feet according to pressure changesreceived by pressure sensors corresponding to the barycenter coordinatesof the user's feet when the user walks; determine a walking distance ofthe user in the virtual scene according to the actual coordinates of thestarting points and the falling points of the user's feet and thecorrespondence relationship between the actual coordinates and the scenecoordinates; and determine a walking speed of the user in the virtualscene according to a time interval between the starting point and thefalling point and the walking distance.
 15. The virtual reality systemaccording to claim 14, wherein the processor is further configured to:determine an initial acceleration according to pressure changes receivedby the pressure sensors corresponding to the barycenter coordinates ofthe user's feet and a weight of the user when the user jumps; determinea jumping height of the user according to a time interval between twoadjacent landings of the user and the initial acceleration; determine ahorizontal displacement of the user according to the barycentercoordinates of the user's feet before leaving the ground and thebarycenter coordinates of the user's feet after landing.
 16. The virtualreality system according to claim 15, wherein the processor is furtherconfigured to adjust the walking distance or the horizontal displacementaccording to an error adjustment parameter.
 17. The virtual realitysystem according to claim 12, wherein the motion device for the virtualreality interaction is configured to: sense the user's motion throughpressure sensors of the running belt and generates motion data; transmitthe motion data of the user to the receiver of the virtual realitydevice through the transmitter; wherein the virtual reality device isconfigured to: process the motion data of the user received by thereceiver through the processor; display a virtual scene image; andadjust the virtual scene image according to the processing of motiondata by the processor.
 18. The virtual reality system according to claim17, wherein the motion data comprises at least one of a walkingdistance, a walking speed, a walking direction, a jumping height, aninitial acceleration, or a horizontal displacement of the user in thevirtual scene.